Frame support structures



March 12, 1963 J. P. BARTLETf FRAME SUPPORT STRUCTURES Filed April 11, 1958 3 Sheets-Sheet 1 INVENTOR JOHN D BAQTLETT March 12, 1963 J. P. BARTLETT FRAME SUPPORT STRUCTURES 3 Sheets-Sheet 2 Filed April I1, 1958 /INVE;NTOR.- JOHN P 154E725 7r March 12, -1963 J. P. BARTLETT 3,080,875

FRAME SUPPORT STRUCTURES Filed April 11, 1958 5 Sheets-Sheet 3 INVENTOR JOHN D BA/QTLETT United States Patent 3,080,875 FRAME SUPPORT STRUCTURES John P. Bartlett, Boston Post Road, South Sudbury, Mass. Filed Apr. 11, 1958, Ser. No. 727,832 7 Claims. (Cl. 135-1) This invention relates to frame support structures for holding flexible covers, and more particularly to such structures and covers as used in the construction of buildings. While not limited thereto, this invention is particularly useful in the construction of greenhouses having plastic covers instead of glass.

It has been the practice to attach a plastic or cloth cover to a wooden frame by means of wooden slats positioned on top of the cover and attached to the frame by nails driven through the slats and the cover into the frame. Such a construction is relatively expensive to maintain, requires a relatively large amount of time to attach the cover to the frame, is difficult to readily be covered without wrinkles in the cover, and may easily have the slats and cover torn from the frame by strong winds.

This invention which substantially reduces or eliminates the foregoing disadvantages, comprises a plurality of elongated substantially rigid support structures or ribs each of which is arched orcurved over a major portion of its length. The flexible cover is held to the ribs by clamping members such as rods which urge the cover against the ribs when the rods are axially stressed and positioned adjacent the ribs. Each of the clamping rods is prevented from moving out of alignment with its respective rib by guide means such as a groove in the rib with the flexible cover being positioned between the clamping rod and the rib.

Since the clamping rods urge the cover into grooves in the ribs, stretching of the cover between the ribs occurs which substantially eliminates wrinkles in the cover. In addition, since no nailing is required to hold the cover to the ribs, they may be made of metal such as aluminum alloy which does not deteriorate thereby substantially reducing maintenance expenditures. Also, since the clamping rods can be made of metal, such as aluminum alloy, they will clamp the cover to the ribs firmly in high winds which would tear a similar cover and its holding slats from a wooden frame.

Other and further objects and advantages of this invention will become apparent as the description thereof progresses, reference being had to the accompanying drawings wherein: p I

FIG. 1 illustrates a front elevation view of a greenhouse embodying the invention;

FIG. 2 illustrates a transverse sectional view of the clamping rod assembly illustrating a further embodiment of the inventionin which the rib has a ridge instead of a groove to hold the clamping rod in alignment with the rib;

FIG. 8 illustrates a side elevation view of a quick action take-up for quickly stressing the clamping rods in place of the thread and nut arrangement shown in FIGS.

5 and 6;

Patented Mar. 12, 1963 FIG. 9 illustrates a front elevation view of the quick action take-up shown in FIG. 8;

FIG. 10 illustrates a transverse sectional view of a further embodiment of the invention showing a rib formed in a semi-circle;

FIG. 11 illustrates a transverse sectional view of a further embodiment of the invention showing a rib formed in a flat curve; and

FIG. 12 illustrates a cross-sectional view of a rib and clamping rod showing a further embodiment of the invention.

Referring now to FIGS. 1 and 2, there is shown a frame structure for a greenhouse made up of a plurality of ribs 10 longitudinally spaced along the greenhouse. Ribs 10 are preferably curved over the major portion of their length, and are attached at their upper ends to ridge pole 11. As shown in FIG. 2, the lower ends of ribs 10 are attached to sills 12, but if desired, may be imbedded in any desired foundation or anchoring structure such as concrete, or may be imbedded in the ground.

A continuous sheet of flexible cover material, shown partially broken away at 13, in FIG. 1, is spread over ribs 10 and ridgepole 11, and is clamped to ribs 10 by clamping rods 14. Cover 13 may be of any desired thickness, and may be of any desired material such :as plastic or cloth, and while preferablytransparent or translucent for greenhouse purposes, may be opaque or light reflecting if the structure is to be used for other purposes such as for a warehouse. A cover found desirable for greenhouse purposes is .004 inch thick polyethylene film.

As shown in detail in FIG. 3, clamping rods 14 are positioned on top of cover 13 and are urged, by tension thereon, into grooves 15 in the upper surface of ribs 10, which have a generally I-shaped cross-section. As also shown in FIGURE 3, the clamping rods 14 are of such curved external contour in the transverse cross section thereof as to fit into a corresponding groove 15 whereby the external contours of the rods 14 and the adjacent curved surface portions of grooves 15 have substantially similar radii of curvature so that the clamping rods 14 fill major portions of the bottoms of the grooves 15 and provide thcrebetween complementary clamp-ing surfaces extending over substantial surface portions of grooves 15. This pulls the cover 13' which is held in frictional engagement between these complementary clamping surfaces taut between longitudinally spaced ribs 10 and eliminates wrinkles. I

Tension on rods 14 may be exerted by any desired means. For example, as shown in greater detail, in FIG. 5, the ends of rods 14 are threaded, as at 16, and extend through holes 17 in a flange 13 extending outward horizontally from sill 12.

Adjustment of nut 19, threaded on portion 16 of rod 14 andengaging the lower side of flange 18, will produce any desired tension of rod 14. Preferably, sufficient tension is exerted on rod 14 to prevent any substantial slippage of cover 13 under rod 14 on rib 10. In practice a rod tension of pounds or so has been found sufficient to prevent slippage of the cover under rods 14. However, tensions up to 2000 pounds may be exerted on the rods 14 to prevent slippage under severe wind conditions.

As shown in FIGS. 5 and 6, the ribs 10 are attached to sill 12 by means of bolts 20 extending through the flanges 21 of ribs 10 and through the sides 22 of sill 12 which as shown here is a U-shaped channel with flanges -18. extending outward from the tops of sides '22. For

As shown in FIG. 4, ridgepole 11 has an inverted Y- shaped cross section. The ends of ribs 10 butt against the vertical portion 26 of the ridgepole, while the flanges 27 of the ridgepole support the lower flanges 21 of ribs 10, and are attached thereto by the bolts 25.

The vertical portion 26 of the ridgepole extends upward to the top of ribs 10 and has notches 28 therein which register with grooves 15 in ribs 10 to allow rods 14 to pass over the ridgepole in grooves 15. The upper edge of ridgepole portion 26 supports the cover 13 between the ribs 10.

Referring now to FIGS. and 6, there is shown a means for clamping the lower edge of the cover 13 to the sill or anchoring structure 12. The cover extends below flange 18, and U-shaped elongated retaining members 29 are urged over flange 18 such that the cover 13 is forced against the upper and lower surfaces and outer edge of flanges 18. Members 29 are slightly shorter than the distance between ribs and are positioned on flange 18 between ribs 10 so that they do not interfere with rods 14. Members 29 preferably clamp the cover 13 to flange 18 tightly by friction. If desired, however, bolts 30 may be used to attach members 29, more securely to flange 18. Cover 13 is punctured to allow rod 14 to pass through it and flange 18.

As shown in FIGS. 1 and 2, purlins 50 may be attached to ribs 10 a few feet above the sills 12. Purlins 50 are shown, by way of example, as angle irons bolted to ribs 10 and running lengthwise of the frame structure to give additional strength and rigidity.

As shown in FIGS. 1 and 2, the end of the greenhouse may have a frame of vertical members 51 such as angle iron to which the end cover portion of 13 is clamped by means of clamps (not shown) similar to clamps 29. Provision may be made in the end for a ventilating fan 39, and one or more doors -38. As shown in FIG. 2, the left hand side of the greenhouse shows a foundation or anchoring structure, by way of example, of concrete blocks 52 through which bolts 24 extend, and the right hand half of the greenhouse shows, by way of example, a foundation, for supporting sills 12, wherein pipes on angle iron members 53 are bolted to sills 12 and are set in concrete footings as at 54. A corrugated metal siding member is then attached to members 5 3 and sills 12.

Referring now to FIGS. 4 and 5, there is shown the details of a means for supporting an inner cover of plastic or other sheet material 33, inside the frame structure of the greenhouse. The cover 3-3 is supported at the ridge 1 1 by a rod 32 running through eyebolt 31 screwed into the lower side of ridge 11. The cover 33 is punctured at eyebolts 31 to allow their engagement with rod 32.

Cover 33 is urged into grooves in the inner or lower flanges 2 1 of ribs 10 by rods 34. As shown in FIG. 4, rods 34 extend to vertical member 26 of the ridge 11 and are held up by flanges 27 of the ridge 11. Axial compression is exerted on rods 34 by nuts 35 threaded on the lower ends of rods 34 and engaging the upper surfaces of inner sill flange 18 with the ends of rods 34 extending through holes provided in flange 18.

The lower edge of sheet 33 may be attached to flange 18 by clamping members 29 and bolts 30 similar to the means for clamping the lower edge of outer sheet 13. Cover 33 is punctured at the upper end of rod 34 to allow rod 34 to extend into groove 15 over flange 2'7. Cover 33 is punctured at the lower end of rod 34 to allow rod 34 to extend through the hole in flange 18. When it is desired to use cover 33, purlins 50 are made of short lengths extending between ribs 10, and are bolted to the upper surface of the inner flange 21 so as not to obstruct the rods 34.

Referring now to FIGS. 8 and 9, there is shown a lever mechanism for more rapidly exerting tension on the ends of rods 14. The ends of rods 14 are headed as at 40 and engage a yoke 41 which is pinned to a clevis lever 42 adjacent the junction of the legs of the clevis. The free ends of the legs of clevis 42 are individually pinned as at 43 to the free ends of the legs of a second clevis 44. A bolt 45 extends upward through a hole in flange 18 and is threaded into the junction of the legs of clevis 44. Adjustment of the tension on rods 14 is adjusted by bolt 18 and the movement of clevis lever 42 will rapidly apply or remove the pre-adjusted tension on rod 14. Yoke 41 is open at one side so that rod 14 may be readily removed therefrom.

Referring now to FIG. 10, there is shown an arched rib shape which is substantially semi-circular. As shown, the rib 47 has the ends thereof imbedded in concrete footings. By way of example, the left hand side of rib 47 is curved down to ground level, while the right hand side has a short substantially vertical side. A ridge pole 48 is bolted to ribs 47 and rods 14 (not shown) pull the cover into grooves in the ribs similar to FIGS. 1 through 6.

Referring now to FIG. 11, there is shown a rib shape where rib 47 is a small portion of a circle with ends imbedded at an angle in concrete as at 49. This produces a structure having relatively low head room suitable for growing plants on the ground.

Referring now to FIG. 7, there is shown a crosssectional view of a rib v10 having projections 36 instead of grooves. The cover 13 is urged against the rib 10 by rods 37 having a U-shaped cross-section complementary to and surrounding the projection 36 to thereby frictionally clamp the cover 13 between the complementary clamping surfaces formed at the rib 10 and the rods 37. Rods 37 are stressed in tension or compression similar to rods 14 and the rib shape can be used in place of any of the ribs in the structures described in FIGS. 1 through 6, 9 or 10.

Referring now to FIG. 12, there is shown a crosssectional view of a rib made from two pipes 55 welded together side by side by weld 56 below the center line of the pipe centers. Rod 14 frictionally holds cover 13 within the groove formed by the upper surfaces of the joined pipes 55 by means of the complementary clamping surfaces formed at the groove constituted by the upper surfaces of the joined pipes 55 and the rods 14. This rib may be used in place of any of the ribs previously described.

While this completes the description of the embodiments of the invention illustrated herein, many modifications thereof will be apparent within the spirit and scope of the invention. For example, portions of the structure not subjected to high wind loads such as the sills or end frames may be made of wood for convenience, side ventilators may be used in place of a fan or in supplement thereto, wire cable may be used in place of tension rods :14, and any desired foundation and end bracing structures may be used. Accordingly, it is intended the invention be not limited except as defined by the appended claims.

What is claimed is:

1. A frame supporting a flexible cover comprising a plurality of arched ribs having a generally I shaped crosssection, means for attaching the outer ends of said ribs to a foundation, the outer side of each of said ribs having a groove therein, the bottom of said groove having a substantially semi-circular cross-sectional shape, a thin cover of deformable material extending in a continuous sheet across a plurality of said ribs and the spaces therebetween, a clamping member positioned in each of said grooves with said cover being positioned between said clamping member and said rib, said clamping member having a substantially circular cross-section of substantially the same size as the bottom of said groove to thereby produce a substantial clamping area between each respective clamping member and said groove, each of said clamping members extending substantially entirely along the outer surface of said arched ribs to points adjacent the outer ends of said ribs, and means attached to the ends of said clamping members for adjustably attaching said clamping members to said means for attaching said ribs to said foundation to thereby produce a longitudinal tension in said clamping members to urge said clamping members into said grooves and thereby produce suflicient frictional engagement with the portions of said cover between said clamping members and said ribs to substantially prevent movement of said cover away from said ribs substantially exclusively by said frictional engagement, to substantially restrain movement of said cover from one side of said ribs to the opposite side thereof in the presence of uneven tensions in the portions of said cover on the opposite sides of any of said ribs.

, 2. In combination an anchoring structure, a plurality of arched elongated substantially rigid, support structures having a curved surface portion forming grooves extending in the direction'of the arches and adapted to receive therein portions of a flexible cover, said support structures being disposed at distances from each "other in the longitudinal direction to define therebetween a plurality of spaces, a flexible cover extending uninterruptedly across said spaces over said support structures, means for urging the portions of said uninterrupted flexible cover into said grooves in frictional engagement with said curved surface portionsincluding a plurality of elongated clamping members adapted to be inserted into said grooves, a clamping member being positioned adjacent a respective curved surface portion to follow the arched configuration thereof,. ea ch of said clamping members being of such curved externalcontour in the transverse cross section thereof so as to fit into said groove, thecross sectional area of said clamping members filling major portions of the bottoms of the grooves, and securing means attached to said clamping members for securely fastening said clamping members to'said anchoring structure and for producing longitudinal stresses in said clamping members to thereby urge said clamping members toward the curved surface portions of said supporting members and thereby clamp said portions of said cover disposed between said complementary clamping surfaces with sufficient force to substantially frictionally retain said cover on said supporting structures.

3. In combination an anchoring structure, a plurality of arched elongated substantially rigid, support structures having curved surface portions forming grooves extend ing in the direction of the arches and adapted to receive therein portions of a flexible cover, said support structures being disposed at distances from each other in the longitudinal direction to define therebetween a plurality of spaces, a flexible cover extending uninterruptedly across said spaces over said support structures, means for urging the portions of said uninterrupted flexible cover into said grooves in frictional engagement with said curved surface portions including a plurality of elongated clamping members adapted. to be inserted into said grooves, a clamping member being positioned adjacent a respective curved surface portion to follow the arched configuration thereof, each of said clamping members being of such curved external contour in the transverse cross section thereof so as to fit into said groove, said curved surface portions and saidexternal contours having substantially similar radii of curvatures over mutually facing portions thereof to provide therebetween complementary clamping surfaces extending over substantial portions of said grooves, and securing means attached to said clamping members for securely fastening said clamping members to said anchoring structure and for producing longitudinal stresses in said clamping members to thereby urge said clamping members toward the curved surface portions of said supporting members and thereby clamp said portions of said cover disposed between said complementary clamping surfaces with sufiicient force to substantially frictionally retain said cover on said supporting structures.

4. In combination an anchoring structure having outwardly extending flange means along the sides thereof, a plurality of arched elongated substantially rigid, sup port structures having curved surface portions forming grooves extending in the direction of the arches and adapted to receive therein portions of a flexible cover, said support structures being disposed at distances from each other in the longitudinal direction to define therebetween a plurality of spaces, a flexible cover extending follow the arched configuration thereof, each of said clamping members being of such curved external contour in the transverse cross section thereof so as to fit into said groove, securing means attached to said clamping members for securely fastening said clamping members to said anchoring structure and for producing longitudinal stresses in-said clamping members to thereby urge said clamping members toward the curved surface portions of said supporting members and thereby clamp said portions of said cover disposed between said complementary clamping surfaces with sufiicient force to substantially retain said cover on said supportingstructures exclusively by frictional engagement, and retaining means including substantially U-shaped' elongated retaining members for frictionally clamping the downwardly extending side portions of said cover to said flange means.

5. In combination an anchoring structure having outwardly extending flange means along the sides thereof, a plurality of arched elongated substantially rigid, support structures having a curved surface portion forming grooves extending in the direction of the arches and adapted to receive therein portions of a flexible cover, said support structures being disposed at distances from each other in the longitudinal direction to define therebetween a plurality of spaces, a flexible cover extending uninterruptedly across said spaces over said support structures and downwardly below said flange means along the sides thereof, means for urging the portions of said uninterrupted flexible cover into said grooves in frictional engagement with said curved surface portions including a plurality of elongated clamping members adapted to be inserted into said grooves, a clamping member being positioned adjacent a respective curved surface portion to follow the arched configuration thereof, each of said clamping members being of such curved external contour in the transverse cross section thereof so as to fit into said groove, the cross sectional area of said clamping members filling major portions of the bottoms of the grooves, securing means attached to said clamping members for securely fastening said clamping members to said anchoring structure and for producing longitudinal stresses in said clamping members to thereby urge said clamping members toward the curved surface portions of said supporting members and thereby clamp said portions of said cover disposed between said complementary clamping surfaces with sufiicient force to substantially frictionally retain said cover on said supporting structures, and retaining means including substantially U- shaped elongated retaining members adapted to be placed over said flange means for frictionally clamping the downwardly extending side portions of said cover to said flange means.

6. In combination anchoring means, a plurality of arched elongated substantially rigid support structures having curved surface portions forming grooves extending in the direction of the arches and adapted to receive therein portions of a flexible cover, said support structures being disposed at distances from each other in the longitudinal direction to define therebetween a plurality of spaces, a flexible cover extending uninterruptedly across said spaces over said support structures, means for urging the portions of said uninterrupted flexible cover into said grooves in frictional engagement with said curved surface portions including a plurality of elongated clamping members adapted to be inserted into said grooves, a clamping member being positioned adjacent a respective curved surface portion to follow the arched configuration thereof, each of said clamping members being of such external contour in the transverse cross section thereof so as to fit into said groove, said clamping members exerting substantial abutting pressure against major interior surface portions of said grooves with substantial components of said pressure extending in mutually opposite directions transverse to said clamping members, and securing means attached to said clamping members for securely fastening said clamping members to said anchoring means and for producing longitudinal stresses in said clamping members to thereby urge said clamping members toward the curved surface portions of said supporting members and thereby clamp said portions of said cover disposed between said complementary clamping surfaces with suflicient force to substantially frictionally retain said cover on said supporting structures.

7. In combination anchoring means, a plurality of arched elongated substantially rigid support structures having curved surface portions forming grooves extending in the direction of the arches and adapted to receive therein portions of a flexible cover, said support structures being disposed at distances from each other in the longitudinal direction to define therebetween a plurality of spaces, a flexible cover extending uninterruptedly across said spaces over said support structures, means for urging the portions of said uninterrupted flexible cover into said grooves in frictional engagement with said curved surface portions including a plurality of elongated clamping members adapted to be inserted into said grooves, a clamping member being positioned adjacent a respective curved surface portion to follow the arched configuration thereof, each of said clamping members being of such external contour in the transverse cross section thereof so as to fit into said groove, said clamping members exerting substantial abutting pressure against major transversely curved interior portions of said grooves, and securing means attached to said clamping members for securely fastening said clamping members to said anchoring means and for producing longitudinal stresses in said clamping members to thereby urge said clamping members toward the curved surface portions of said supporting members and thereby clamp said portions of said cover disposed between said complementary clamping surfaces with sufficient force to substantially frictionally retain said cover on said supporting structures.

References Cited in the file of this patent UNITED STATES PATENTS 588,773 Mitchell Aug. 24, 1897 825,665 Kram July 10, 1906 1,683,421 Sodergren Sept. 4, 1928 2,363,916 Waterman et a1 Nov. 28, 1944 2,411,316 Capita Nov. 19, 1946 2,497,596 Frieder et al. Feb. 14, 1950 2,827,138 Roy Mar. 18, 1958 FOREIGN PATENTS 320,280 Great Britain Oct. 10, 1929 

2. IN COMBINATION AN ANCHORING STRUCTURE, A PLURALITY OF ARCHED ELONGATED SUBSTANTIALLY RIGID, SUPPORT STRUCTURES HAVING A CURVED SURFACE PORTION FORMING GROOVES EXTENDING IN THE DIRECTION OF THE ARCHES AND ADAPTED TO RECEIVE THEREIN PORTIONS OF A FLEXIBLE COVER, SAID SUPPORT STRUCTURES BEING DISPOSED AT DISTANCES FROM EACH OTHER IN THE LONGITUDINAL DIRECTION TO DEFINE THEREBETWEEN A PLURALITY OF SPACES, A FLEXIBLE COVER EXTENDING UNINTERRUPTEDLY ACROSS SAID SPACES OVER SAID SUPPORT STRUCTURES, MEANS FOR URGING THE PORTIONS OF SAID UNINTERRUPTED FLEXIBLE COVER INTO SAID GROOVES IN FRICTIONAL ENGAGEMENT WITH SAID CURVED SURFACE PORTIONS INCLUDING A PLURALITY OF ELONGATED CLAMPING MEMBERS ADAPTED TO BE INSERTED INTO SAID GROOVES, A CLAMPING MEMBER BEING POSITIONED ADJACENT A RESPECTIVE CURVED SURFACE PORTION TO FOLLOW THE ARCHED CONFIGURATION THEREOF, EACH OF SAID CLAMPING MEMBERS BEING OF SUCH CURVED EXTERNAL CONTOUR IN THE TRANSVERSE CROSS SECTION THEREOF SO AS TO FIT INTO SAID GROOVE, THE CROSS SECTIONAL AREA OF SAID CLAMPING MEMBERS FILLING MAJOR POR- 